We are 10 miles away, but we are stuck on an anchor and ccan not assist. This happened @ 2145. Ten minutes after the mayday, they abandoned ship and the flames were at least 200' tall. It's still raging and it's 0130 in the morning now. I called Transocean when it happened and they were not aware, but the Coast Guard just called them, I updated them. So, I gave them my assessment. Several vessels are conducting search patterns at this time. The head count on the rig was reported to be 129, but there has not been a hard count on the radio. We are going to the location within the hour.